I have looked through the SMLNJ User Guide and can't find anything about debugging capabilities. I'd love to just see a stack trace, or step through a function. Is this possible. Are there other implementations for similar variants of SML that do provide this feature?
From section 3.3 of the SMLNJ faq:
Q: Is there a debugger for SML/NJ? What ever happened to Tolmach's debugger for SML/NJ 0.93?
A: The short answer is no.
Debugging SML * For years, no one had an SML debugger * Why? o No one had any bugs? o It is hard to write a debugger for SML o The user community wasn’t large enough * Likely all three are true
There's a .NET compiler, though, which claims to have some debugging support..